This invention relates to a character display device for displaying some characters in reverse to indicate some printing effects such as boldface, or for block-editing text.
The character display device of this type has a display, such as a cathode-ray tube (CRT) display, a liquid-crystal panel, an electroluminescent (EL) panel, or a plasma display. It typically displays characters with a dot matrix. When the number of dots for each character is limited, a character with printing effects such as boldfacing, shadowing and striking-out can not be displayed as it is. Instead, those enhanced characters are displayed in reverse on the monochromatic display.
In these display devices, an underline is displayed at the bottom of the character region. If the reversed character has an underline, the underline is also reversed, which causes a problem. As shown in FIG. 5A, when an enhanced character (e.g., a boldface character) with an underline is reversed ("I" and "T"), the underline of the reversed characters is not displayed. If these characters are placed between normal (unenhanced) characters with an underline, the underline appears interrupted. This produces a display image different from the printing image. On the other hand, as shown in FIG. 5B, when an enhanced character without an underline is reversed, an unnecessary underline is displayed under the reversed character, resulting in confusion over whether it is underlined. That is, in these cases, visual recognition of an underline is difficult while editing a text.